checkmark == none ignores ischecked.

native/Avalonia.Native/src/OSX/menu.h

@@ -32,6 +32,7 @@ private:
     IAvnActionCallback* _callback;
     IAvnPredicateCallback* _predicate;
     bool _isSeperator;
+    bool _isCheckable;
     
 public:
     FORWARD_IUNKNOWN()

native/Avalonia.Native/src/OSX/menu.mm

@@ -70,6 +70,7 @@
 
 AvnAppMenuItem::AvnAppMenuItem(bool isSeperator)
 {
+    _isCheckable = false;
     _isSeperator = isSeperator;
     
     if(isSeperator)
@@ -157,7 +158,7 @@ HRESULT AvnAppMenuItem::SetIsChecked (bool isChecked)
 {
     @autoreleasepool
     {
-        [_native setState:(isChecked ? NSOnState : NSOffState)];
+        [_native setState:(isChecked && _isCheckable ? NSOnState : NSOffState)];
         return S_OK;
     }
 }
@@ -169,12 +170,21 @@ HRESULT AvnAppMenuItem::SetToggleType(AvnMenuItemToggleType toggleType)
         switch(toggleType)
         {
             case AvnMenuItemToggleType::None:
+                [_native setOnStateImage: [NSImage imageNamed:@"NSMenuCheckmark"]];
+                
+                _isCheckable = false;
+                break;
+                
             case AvnMenuItemToggleType::CheckMark:
                 [_native setOnStateImage: [NSImage imageNamed:@"NSMenuCheckmark"]];
+                
+                _isCheckable = true;
                 break;
                 
             case AvnMenuItemToggleType::Radio:
                 [_native setOnStateImage: [NSImage imageNamed:@"NSMenuItemBullet"]];
+                
+                _isCheckable = true;
                 break;
         }